Direct transitive closure algorithms: design and performance evaluation

Abstract

We present new algorithms for computing transitive closure of large database relations. Unlike iterative algorithms, such as the seminaive and logarithmic algorithms, the termination of our algorithms does not depend on the length of paths in the underlying graph (hence the name direct algorithms). Besides reachability computations, the proposed algorithms can also be used for solving path problems. We discuss issues related to the efficient implementation of these algorithms, and present experimental results that show the direct algorithms perform uniformly better than the iterative algorithms. A side benefit of this work is that we have proposed a new methodology for evaluating the performance of recursive queries.